dc.description.abstract | Geotechnical engineers usually encounter large-scale slope problems with complex material composition. Thus, it is hard to use full-size in-situ test to observe the failure mechanism. By law of similitude and simplification, model tests were established to simulate 1-g gravitational field or n-g gravitational field by shaking table test or centrifuge test. This study utilized to the large-scale model slope shaking table tests of the model slope conducted by Lin and Wang from 2003 to 2009 at NCREE. The failure time was estimated according to the acceleration response record, particle image velocimetry (PIV) analysis, and marker displacement measurements. The failure plane was estimated from results of the finite differentice analysis. The critical acceleration and failure time was estimated based on stress path and frequency spectrum analysis during loading. By using the numerical analysis, the effects of vertical vibration or not were discussed.
Shallow failure sliding occurred on the slope surface, no significant displacement on the crest and toe, and no obvious difference in acceleration responses were observed. As deep-seated landslide developed, the crest and toe started moving down-slope. The crack occurred behind the crest, and phase of acceleration response became shifted. The failure time was defined when the grid start to deform in deeper. The failure surface was defined by maximum shear strain distribution which is from toe to crest and the stress of grids close to failure envelope. Based on results of numerical simulation of specimen which is without vertical vibration and specimen which is with vertical vibration, it was found that the range of horizontal displacement and shear strain increment of specimen with vertical vibration is more than specimen without vertical vibration.At last, compared with acceleration history and failure behavior were made to determine, find out the mode of shallow failure, deep failure, and failure time, then summarize the data of large shaking table test. | en |